1. Field of the Invention:
The present invention relates to a method of manufacturing a miniature tipless halogen lamp of a diameter within the range of some 1.0 to 4.0 mm, capable of radiating intensive white light and being employed in apparatus employing an optical fiber cable, such as sensors, automatic controllers, industrial robots and medical appliances, particularly, endoscopes, for illumination through an optical fiber cable, and an apparatus for carrying out the method.
2. Description of the Prior Art:
In manufacturing a conventional miniature halogen lamp, a gas introducing pipe (designated generally as "tip" in the related industry, and hence will be referred to as "tip" hereinafter) is fused off to seal the lamp bulb after introducing a gas into the lamp bulb. Accordingly, when the internal pressure of the lamp bulb increases above the atmospheric pressure due to heating for fusing-off the tip and the resultant thermal expansion of the gas introduced into the lamp bulb, the gas spouts through the fused tip, and hence it is impossible to seal the lamp bulb. Therefore, when the internal pressure of the lamp bulb needs to be higher than the atmospheric pressure, the lamp bulb containing the gas needs to be cooled by liquid nitrogen or the like in sealing the lamp bulb by fusing-off the tip. Furthermore, according to the prior art, since a discharge pipe and the tip are provided in the head or the bottom of the lamp bulb and the discharge pipe and the tip are fused off after use, the traces of the discharge pipe and the tip remains inevitably in the finished lamp. Still further, when the tip is formed in the head of the lamp bulb, it is impossible to formalize the lamp as the natural consequence, while it is impossible to form the tip in the bottom of the bulb because the lead wires need to be provided in the bottom of the bulb with a very small gap therebetween to form a very small lamp. Accordingly, it has been impossible to provide a lens in the head of a miniature halogen lamp or to formalize miniature halogen lamps.